1. Field of the Invention
This invention relates to a sports ball, and more particularly to an inflatable ball with a rib structure.
2. Description of the Related Art
A bladder of a conventional inflatable sports ball is made from either synthetic or natural rubber. To prevent swelling or deformation of the bladder due to increase of the inflation pressure, the following three manufacturing methods are usually employed:
1. Wrapping Yarns Around the Rubber Bladder
Referring to FIG. 1, a conventional inflatable ball includes a rubber bladder 1, a wrapping yarn layer 2 covering an outer surface of the rubber bladder 1, and a rubber outer cover layer 3 covering the wrapping yarn layer 2.
Referring to FIG. 2, another conventional inflatable ball includes a rubber bladder 1, a wrapping yarn layer 2 covering an outer surface of the rubber bladder 1, and an outer cover layer 301 covering the wrapping yarn layer 2 and made from a plurality of sewn leather pieces.
Referring to FIG. 3, still another conventional inflatable ball includes a rubber inner bladder 1, a wrapping yarn layer 2 covering an outer surface of the rubber inner bladder 1, a rubber outer bladder 4 covering the wrapping yarn layer 2, and a plurality of adhering pieces 5 fixed to an outer surface of the rubber outer bladder 4 and made of a PU (polyurethane) or leather material.
2. Wrapping a Fabric Cloth Layer Around the Rubber Bladder
Referring to FIG. 4, a conventional inflatable ball includes a rubber bladder 1, a fabric cloth layer 6 covering an outer surface of the rubber bladder 1 and made from a plurality of interconnected fabric cloth pieces 601, and a rubber outer cover layer 3 covering the fabric cloth layer 6.
Referring to FIG. 5, another conventional inflatable ball includes a rubber bladder 1, a fabric cloth layer 6 covering an outer surface of the rubber bladder 1 and made from a plurality of interconnected fabric cloth pieces 601, and an outer cover layer 301 covering the fabric cloth layer 6 and made from a plurality of sewn leather pieces.
Referring to FIG. 6, still another conventional inflatable ball includes a rubber inner bladder 1, a fabric cloth layer 6 covering an outer surface of the rubber inner bladder 1 and made from a plurality of interconnected fabric cloth pieces 601, a rubber outer bladder 4 covering the fabric cloth layer 6, and a plurality of adhering pieces 5 fixed to an outer surface of the rubber outer bladder 4 and made of a PU or leather material.
3. Attaching Fabric Lining Layers to an Inner Surface of an Outer Cover Layer
Referring to FIG. 7, a conventional inflatable ball includes a rubber bladder 1, an outer cover layer 7 covering the rubber bladder 1 and made from a plurality of sewn leather pieces 701, and a plurality of fabric lining layers 703 adhered to an inner surface of the outer cover layer 7.
Although the aforesaid methods can prevent over-inflation or deformation of the bladder, many devices, manufacturing procedures, and laborers are required to complete a production. Further, the rubber bladder 1, the rubber outer cover layer 3 or the rubber outer bladder 4 after vulcanization at high temperature changes its molecular structure, so that the chance of being recycled is low. Moreover, many kinds of additives (such as sulfur) must be mixed with the raw rubber before vulcanization at high temperature may be performed. During this process, contamination is likely to occur, and offensive odor is created during burning, thereby causing harmful effects on human body.